This invention concerns engine fuel injector installations and more particularly arrangements for retaining a fuel injector in position in a predetermined rotative orientation in a fuel rail injector seat.
Engine fuel injectors are generally cylindrical valve assemblies which are typically installed in seats formed in a fuel rail. The fuel rail is supplied with fuel under pressure, which is directed into the engine cylinders through the fuel injectors. Each fuel injector has a valve needle moved to open and close an orifice in a valve seat by operation of a solenoid coil energized by the engine electronic controls.
In manifold injection engine applications, the fuel injectors should preferably be in a particular rotative orientation in order to provide an optimal relationship of the fuel spray pattern with the associated intake valve.
It has heretofore been known to use clips to retain each fuel injector in its fuel rail injector seat so as to be able to resist the fuel pressure exerted on the injector, and at the same time hold the injector in the desired rotative orientation.
U.S. Pat. No. 5,136,999 issued on Aug. 11, 1992 for "Fuel Injection Device for Internal Combustion Engines" describes such an installation.
In one design, a U-shaped clip has slots which capture fuel rail projecting features to be axially locked thereto. This clip is also properly rotatively oriented by clip corners engaging fuel rail projections adjacent the injector seat. The clip in turn also has spaced legs formed with tabs formed with arcuate edges which are received in a fuel injector slot to axially lock the fuel injector in place. To rotatively orient the injector with respect to the clip, there is a flat on each tab edge which engages a flat surface on either side of the injector groove.
When installing the electrical connectors or working with the wiring harnesses, turning forces can be inadvertently applied to the fuel injectors tending to rotate them out of their correct orientation. The engagement between the injectors and clips typically is such that the clip legs tend to be spread apart by the turning forces. If excessive force is applied, the clip can be forced out of an injector body groove used as the axial locking feature, and also can be permanently deformed so at to no longer retain the injector properly.
In addition, the engagement features on the clip and fuel rail adjacent the injector seat also may tend to spread open the clip legs when the injector is turned. The net effect is to reduce the reliability of the arrangement for holding the installed fuel injectors in the proper rotative position.
Accordingly, it is an object of the present invention to provide an improved clip retention arrangement for fuel injectors which much more reliably functions to properly orient the fuel injector in a fuel injector seat.